If it helps, here is the context in which I am trying to get the value:

using Archetype.Models;
using Newtonsoft.Json;
using nuPickers;
using Rhythm.Extensions.Helpers;
using System;
using System.ComponentModel;
using System.Globalization;
using System.Linq;
using Types;
using Umbraco.Core;

public class LinkConverter : TypeConverter
{
    public override bool CanConvertFrom(ITypeDescriptorContext context,
        Type sourceType)
    {
        return true;
    }

    public override object ConvertFrom(ITypeDescriptorContext context,
        CultureInfo culture, object value)
    {

        if (value is string)
        {
            value = JsonConvert.DeserializeObject<ArchetypeModel>(value as string);
        }

        var model = (value as ArchetypeModel).FirstOrDefault();
        var alias = model.Alias;
        if ("contentLink".InvariantEquals(alias))
        {

            var strNodeId = model.GetValue<string>("linkPage");
            if(!string.IsNullOrWhiteSpace(strNodeId))
            {
                var nodeId = int.Parse(strNodeId);
                var helper = ContentHelper.GetHelper();
                var node = helper.TypedContent(nodeId);
                if (node != null)
                {
                    var suffix = model.GetValue<string>("linkSuffix");
                    var url = node.Url + suffix;
                    // null
                    var one = model.GetValue<Picker>("newWindow");
                    // [{"key":"True","label":"Open in New Window"}]
                    var two = model.GetValue<string>("newWindow");
                    return new Link()
                    {
                        Label = model.GetValue<string>("linkLabel"),
                        NewWindow = false,//TODO: Hardcoded until I can resolve a bug.
                        Title = model.GetValue<string>("linkTitle"),
                        Url = url
                    };
                }
            }
        }
        //TODO: Other link types.

        return null;
    }

}

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